Double-throw switch



June 25, l929- J. c. sTEARNs 1.718.717

DOUBLE THROW SWITCH Filed nec. 10.l 1926 the other to constitute a dimmer.

Patented June 25, 1929.

PATENT OFFICE.

JASON C. STEARNS, OF WORCESTER, MASSACHUSETTS.

DOUBLE-THROW SWITCH.

Applicationiled December 10, 1926. Serial No. 153,957.

This invention relates to a double t-hrow switch for :general purposes in which the switch is operated by pressing on a plunger.

The principal objects of the invention are to provide a simple device/of this character in which the plunger is pressed down in the same way irrespective of the position of the switch at the time or the way in which it is connected; to provide a pivoted switch member adapted to swing to two posit-ions only and having rigid slant'ing surfaces to receive the pressure of the plunger; to provide a spring plunger having a rigid operating end mounted to swing freely to accommodate the position of the switch member and operate it positively in either direction; and to provide an arrangement which cannot get stuck on a dead center.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings in which Fig. 1 is a sectional view of a switch casing embodying this invention with the plunger in central section showing the parts in half of the casing in elevation and illustrating a normal position of the switch;

Fig. 2 is a sectional view on the line 2 2 of Fig. 1;

Fig. 3 is a sectional view similar to Fig. 1 showing the plunger in the positionof starting to turn the switch from the position shown in Fig. 1;

Fig. 4 is a similar view showing the plunger pushed in further and just ready to snap the switch; andY Fig. 5 is a ltransverse sectional view on the line 5 5 of Fig. 1.

The. electrical connecting part of the switch comprises two terminals 10 having convex contact terminal surfaces. They may be connected up with mains 12 direct-ly or in any desired way. The main may be connected to two lamps. one of lower candle power than The. contact member 1i is pivoted on a stud or pivot 15 and capable of swinging thereon from Contact with one convex terminal 10 to the other convex terminal and back. This pivot stud 15 is shown in the form of a binding screw and is connected with a supply main 11.

On the contactor 1:4: is a rigid metallic member 16 of sheet metal preferably having two surfaces at angles to each other and symmetrically located with respect to the Contact member 14. At its ends are two iianges 17 extending at right angles to the respective walls at the center. The contact member also has a part at the end pressed out to form a concave seat 18 for engaging the convex contacting points 1() so that it will normally stay in position whenswitched to either point. This member 14 is of spring metal and is so set that it presses with some force on these contacts with a coil spring 13 behind it.

The operating means comprises a plunger 20 having a shoulder under which is the end of a coil spring 21 surrounding the shank of the plunger and yieldingly pressing against a loose sheet metal member 22. This member has a general triangular shape and is provided with two arms, forming two sides of the triangle, and together holding between them a strong piece 23 of insulating material which is beveled at its edge and is arranged to contact the sides of the sheet metal member 16 above described. The shank of the plunger 20 slides freely through an opening in the member 22 and hasia fiat head 24 which has room enough to move within the triangular member 22. This plunger is provided'with a cap 25 fixed thereon and having a spring 2Gv inside and bearing on the inner side of the cap and also bearing at its end on the wall 27 of the casing 28 in which the device is located. lVthin this spring is a fixed tubular member 30 surrounding the spring 21 and serving as a stop for the cap25. In the casing 28 are two walls 29 spaced apart for engaging the opposite ends of the base of the triangle 22.

The casing 28, as stated, is provided with plate 27 which i? perforated for securing to a, wall or dash and the electrical parts above described are mounted on an insulating plate 19 which constitutes the rear of the casing.

In operation, assume that the parts are in the position shown in Fig., 1 and it is desired to change the current, as to dim the light, the operator presses on the cap 25. The first effect of this is to move the parts without much resistance into the position shown in Fig. 3. It will be noticed that the insulating plate 23 engages the slanting Wall of the member 16. Being connected with the plunger4 only by the resistance ofthe spring 21, it isdeflected out of its normal [central position toa point where its angularopposite extreme, this insulating member would engage the opposite side in the same way and turn its side ways. But'now, starting again from the posit-ion shown in Fig. 3 and pressing further on the cap 25, it will come down with its edge against the plate 27 fully compressing the spring 26 and' further compressing the spring 21 until the parts'come into the position shown in Fig. 4. Just as the cap comes down to the plate 27 the head 24 reaches the rear end of the operating member 23. Now the direct force of the hand applied to the cap turns the member 16 and the contacting plate 14 suddenly from the position shown and swings it over to the opposite position where the concave surface 18 rides over the convexsurface 16 of that terminal. Thus the switch is.

reversed without danger of its being dislodged or shaken. It is the resistance of the springs 13 and 18 and the fitting of these concave and convex surfaces that prevents the eontactor 14 from turning ,as long as it is acted upon only by spring pressure.

The pressure on the plunger is nowvreleased and the parts go back to the position shown in Fig. 1 except that the switch is reversed. When so reversed the next operation of the plunger will act in the same way but in the opposite direction to turn it back to the dotted position shown in Fig. 1.

This switch constitutes a very effective means for holding the terminals in either one of their extreme positions; prevents the accidental reversal of the switch when the plunger is pressed in only part way; provides an instantaneous operation when it is finally pressed in fully; prdvides a switch in which there is no possibility of the oscillating member being left part way between the two terminals, and also provides many features connected with the guiding and mounting of the parts as will appear from thevabove description.

Although I have illustrated and described only a single 'form of the. invention I am aware of the fact that modifications can be made therein by any erson'skilled in the art without departing om the scope of the invention as expressed in the claims. Therefore, I do not wish to be limited to all the details of construction herein shown and described, but what I do claim is Y \1. In a double throw switch, the combination with a pair of terminals spaced apart, of apiv'oted contact member movable from one terminal tothe other and having flanges at its outer ends, a plunger for operating the switch having a shank provided with a spring thereon, and a member loosely mounted on and carried by the plunger under the spring and having between its two sides ,a rigid operating piece for engaging the flanges and turningthe switch.

2. In an.electric switch, the combination with a pair of terminals spaced apart, of a pivoted eontact'member movable from one terminal to the other and having inclined Walls symmetrically located thereon with flanges at their outer ends, a plunger for operating the switch having a shank provided with a spring thereon, a member of general y triangular form loosely mounted on the plunger under the spring, a rigid operating piece carried by the triangular `member for engaging theinclined surfaces and turning the switch, and a pair of walls between which the base of the triangular member is confined to limit its motion and assist in guiding it to shift on the shank of the plunger, in accordance with the direction in which the I operating piece, tends.Y to move when the plunger is forced in.

3. In a double throw switch, the combinaplunger, the switch having inside it twg walls connected with said tubular member for engaging the opposite ends of the base of the triangular member and guiding it.

4. In a switch, the combination of a plunger having a shank provided with a spring thereon, the shank also having a head, i

a loose member having a perforation for receiving the shank and located between the spring and the head so as to be free to move sideways and to swing with respect tothe shank, said loose member having a rigid piece thereon for operating the switch, the switch lhaving inside it two walls for engaging the opposite ends of the base of the loose member and guidingit, whereby when the-plunger is depressed the rigid piece will move freely into operating position but will be held by the springs, the head of the plunger being in position to engage the operating piece and positively operate it to turn the switch.

5. In an electric switch, the combination with a terminal, of a pivoted Contact member movable to and from the terminal and having operating the switch having a shank provided With a spring thereon, amember looselymounted on the plunger under the spring,

'an operating piece carried by the last named member is confined to limit its motion and assist in guiding it to shift on the shank of the plunger when the plunger is forced in.

In testimony whereof I have hereunto affixed my signature.

JASON o. STEARNS. 

